This invention relates to the field of electrophotographic printers employing replaceable toner cartridges which are containers holding a supply of toner particles. The toner is fed, by various means, to the development section of the printer. The toner is in powder form that typically has a particle size ranging from 5 microns to 20 microns. The toner is designed to flow freely, which makes it difficult to contain in the toner cartridge during shipping without a seal completely covering the opening. The seals must be able to withstand the rigors of transport and be easily removed by the end user of the cartridge.
Printer cartridges are designed to be compact. As a rule, many toner cartridges have very narrow, openings to the integral toner hopper which makes either manual or automatic seal placement difficult. Many seats use a pressure-sensitive adhesive. When the pressure-sensitive adhesive is exposed prior to insertion, it tends to make placement difficult while maneuvering in a restricted opening, particularly in a manual seal insertion process.
There have been various designs to make such seals easier to insert over the toner cartridge opening. One construction includes a removable cardboard strip with perpendicular tabs on the top surface of the seal. This design provides a rigid support for the seal and a means to grasp the seal for insertion. The disadvantage accompanying this design is that it is still difficult to maneuver the seal into position with the adhesive fully exposed, and it is even more difficult in a manual process in toner cartridges having very narrow access openings. It is not possible to see the whole position of the seal as it is installed because the seal is held by hand, and the hand blocks the view.
The present invention relates to a rigid, removable, extended insertion tool which has a release coating on a surface which engages a portion of the peripherally located adhesive on the seal. The remainder of the adhesive, in this position, is exposed, so that when the seal is inserted in the cartridge to be positioned above the toner opening, a distal portion of the adhesive may be first engaged, following which the tool is disengaged from the seal, and the seal is allowed to drop to the surrounding remaining portion of the toner opening, thus completing the installation. The tool is sufficiently durable that it may be reused many times.
The tool may be made of rigid material such as plastic or metal, and is of length slightly smaller than the length of the seal to be installed. It is also slightly wider than the toner cartridge opening, so that the end portions may extend beyond the toner cartridge opening. It is preferable to place a physical stop on the planar portion of the tool which forms a shoulder so that the seal may be positioned on the planar portion of the tool with the correct amount of seal overhang leaving a distal portion of the adhesive exposed for initial positioning on a distal edge of the toner hopper opening.
The installation process is to first remove the seal release liner covering the pressure-sensitive adhesive. The seal may then be placed on the planar portion of the tool having the release coating. The tool and seal are then inserted into the toner cartridge opening so that the exposed adhesive of the seal is positioned on the distal edge of the toner cartridge opening. That part of the seal is pressed down to adhere the seal to the distal edge of the opening. The tool is then removed by moving the distal edge downwardly to peel the engaged adhesive of the seal away from the release coating on the tool.
Briefly stated, the invention contemplates the provision of a novel tool and method for installing a known toner seal on the mouth of a toner hopper opening wherein the tool detachably supports the seal during positioning in such a manner the a distal portion of the peripheral adhesive surface of the seal overlies a corresponding distal portion of a surface surrounding the toner hopper opening so that the adhesive surface may be engaged while the seal is still supported by the tool, using an elongated probe if necessary to press the adhesive into place. The seal is then detached from the tool so that the proximal portion of the adhesive surface may drop to engage a corresponding surface surrounding the toner opening, again using the auxiliary probe, if necessary. Once detached, the tool may be reused.